With recent developments in ignition systems for vehicles, particularly automobiles, electronic ignition systems are now the standard in the industry. With this development, one of the more popular embodiments has been to provide each spark plug, or indirectly each combustion chamber, with its own ignition coil. These are referred to as coil-per-plug (CPP) type ignition coils. Such a design is seen in U.S. Pat. No. 5,241,941, assigned to the assignee of the present invention. The coil housing includes a stem at its bottom end through which projects the secondary coil, or high voltage, output terminal into which, by some means, the electrical output must be passed to the center electrode of the spark plug. Conventionally, a coil spring is used which is in light, non-secured contact with the high voltage output terminal and which lightly snaps over the head of the center electrode of the spark plug. The spring is maintained in place by a concentrically disposed and enclosing rubber boot which is expanded onto the housing output terminal stem at one end and over the spark plug center electrode at the other end to virtually hold the assembly of coil spring in place.
Nevertheless, the electrically conductive coil-type compression spring is not secured to the high voltage output terminal. Rather, it bears against the output terminal under the designed compression of the spring when the coil housing and spark plug are each secured to the engine.